Camming means for rotary motion apparatus



Nov. 27, 1962 M. J. KRAWACKI 3,065,709

CAMMING MEANS FOR ROTARY MOTION APPARATUS Original Filed Nov. 18, 1959 7Sheets-Sheet 1 INVENTOR. MICHAEL J. KRAWACKI his ATTORNEYS Nov. 27, 1962CAMMING MEANS FOR ROTARY MOTION APPARATUS Original Filed Nov. 18, 1959 7Sheets-Sheet 2 INVENTO MICHAEL J. KRAW Kl his v ATTORNEYS M. J. KRAWACKI3,065,709 A Nov. 27, 1962 M. J. KRAWACKI CAMMING MEANS FOR ROTARY MOTIONAPPARATUS v QM Ongmal Flled Nov 18 ATTORNEYS Nov. 27, 1962 KRAWACKI3,065,709

CAMMING MEANS FOR ROTARY MOTION APPARATUS Original Filed Nov. 18, 1959 7Sheets-Sheet 4 FIG 7 INVENTOR. MICHAEL J. KRAWACKI BY emw l, 4m,

Nov. 27, 1962 M. J. KRAWACKI 3,065,709

CAMMING MEANS FOR ROTARY MOTION APPARATUS Original Filed Nov. 18, 1959 7Sheets-Sheet 5 s j/Zp( 0.350, 020H) 0 his Arman 51's Nov. 27, 1962 M. J.KRAWACKI 3,065,709

CAMMING MEANS FOR ROTARY MOTION APPARATUS Original Filed Nov. 18, 1959 7Sheets-Sheet 6 INVENTOR.

. MICHAEL J. KRAWACKI m=90 BY 41 his ATTORNEYS Nov. 27, 1962 M. .1.KRAWACKI CAMMING MEANS FOR ROTARY MOTION APPARATUS '7 Sheets-Sheet '7Original Filed Nov. 18, 1959 INVENTOR. MICHAEL J. KRAWACKI BY '15 4 a,

his ATTORNEYS United States Patent Ofiice 3,065,709 Patented Nov. 27,1962 3,065,709 CAMMING MEANS FOR ROTARY MOTION APPARATUS Michael J.Krawacki, Engiishtown, N..I., assignor to Trojan Corporation,Plainfield, N.J., a corporation of New Jersey Original application Nov.18, 1959, Ser. No. 853,912. Divided and this application Jan. 27, 1960,Ser. No. 4,972 Claims. (Cl. 103139) This invention relates generally toapparatus, such as fluid pumps and motors, in which there occurs anenergy transfer between a mechanical part and a liquid or gaseous fluid.More particularly, this invention relates to apparatus of this sortwhich is characterized by aligned impulsion and rotary motion. Thepresent application is a division of my copending application Serial No.853,912 filed November 18, 1959. The last-named application is acontinuation-in-part of my copending application Serial No. 813,592=filed May 15, 1959 which, in turn, is a continuation-in-part of myco-pending application Serial No. 775,244 tiled November 20, 1958, nowabandoned.

By aligned impulsion is meant an energy transfer action between amechanical part and a fluid wherein the fluid impels the part or isimpelled thereby, and wherein the motion of the part is aligned indirection with the movement of the fluid in the course of the energytransfer action. Such alignment is present, for example, in areciprocating steam engine wherein the motion of the piston is alignedwith the direction of expansion of the steam in the cylinder. It is notpresent in turbo-pumps or turbo-motors wherein the motion of therotating blades is at right angles to the direction of travel of thefluid contained within the pump or motor. Hence, in respect to thefeature of aligned impulsion, the apparatus to which this inventionrelates is like reciprocating fluid pumps or engines, and unliketurbo-pumps or turbo-motors. However, the apparatus of the presentinvention is unlike reciprocating machines, and like tunbopumps orturbo-motors, in that it is characterized by rotary motion. Hence, theapparatus to which this invention relates is rotary motion, alignedimpulsion apparatus which combines in one machine the advantage found inreciprocating machines of the high efliciency which is provided by thealigned impulsion, and, also, the advantages found in turbo-machines(and which is provided by the rotary motion) of unidirectionalcontinuous operation and of freedom both from mechanical vibration andfrom fluid vibration (pulsation).

The principal elements of one such rotary motion, aligned impulsionmachine are shown schematically in the accompanying first two figures ofthe figures listed below wherein:

FIG. 1 is a partially cut away and plan view of ap paratus according tothe invention, as such apparatus may be generally represented.

FIG. 2 is a vertical cross section, taken as indicated by the arrows 22in FIG. 1, of such apparatus as it may be generally represented;

FIG. 3 is an end elevation in cross section of an exemplary practicalembodiment of a machine according to the invention, the View in FIG. 3excluding the outer housing for such machine and being taken asindicated by the arrows 3--3 in FIG. 4;

FIG. 4 is a front elevation in cross section of the FIG. 3 machine, thecross section being initially taken as indicated by the arrows 4-4 inFIG. 3, and the upper slanting face of such cross section being thenrotated into line with the lower vertical face thereof to arrive at theview of FIG. 4, this view including the outer housing for the machine;

2, FIG. 5 is a developed plan view, taken over the angular intervalindicated by the arrows 55 in FIG. 3, of the embodiment of FIG. 3;

FIG. 6 is an isometric view showing in schematic form one of the vanesin the FIG. 3 embodiment, and the forces exerted on such vane;

FIG. 7 is a schematic view in side elevation of a vane in a machine ofthe type shown in FIG. 3, and of the action of forces thereon;

FIG. 8 is a schematic plan view of a vane in a machine of the type shownin FIG. 3, and of the action of forces thereon;

FIG. 9 is a detail view in front elevation and partially in crosssect-ion, of a modified vane of the FIG. 3 machine;

FIG. 10 is a view in cross section taken as indicated by the arrows10-l0 in FIG. 9 of the modified vane;

FIG. 11 is a view in cross section, taken as indicated by the arrows11-11 in FIG. 9 of the modified vane;

FIG. 12 is a view in side elevation and vertical cross section showingin detail the cooperation between a vane and a reaction block in theFIG. 3 embodiment;

FIG. 13 is a plan view showing deatils of a reaction block in the FIG. 3embodiment;

FIG. 14 is a view in front elevation and in vertical cross section,taken as indicated by the arrows 1414 in FIG. 13, of the reaction blockshown in FIG. 13;

FIGS. 15A and 15B are adaptations of the developed view in FIG. 5 andare schematic diagrams of aid in explaining certain quantitativerelations inhering in the FIG. 3 machine;

FIG. 16 is a schematic diagram of a cross section of a machine of thetype shown in FIG. 3, the diagram.

supplementing FIG. 15 as an explanatory aid, and being representative ofa rotary motion, aligned impulsion.

machine having one reaction block and two vanes;

FIG. 17 is a schematic diagram of a cross section of a machine of thetype shown in FIG. 3, the diagram sup-' plementing FIGS. 15 and 16 as anexplanatory aid, and being representative of a machine having tworeaction blocks and four vanes;

FIG. 18 is a developed view corresponding to the de-,

veloped views of FIGS. 5 and 15 and showing the extent of the cammingintervals in the FIG. 3 machine;

FIG. 19 is a schematic diagram of a cross section ofv the FIG. 3 machineas modified to have six vanes; and? FIG. 20 is a schematic diagram of across section of;

the FIG. 3 machine as modified to have twelve vanes.

In FIGS. 1 and 2 which illustrate thev general character of the type ofapparatus to which this invention relates,; the numbers 20 and 21 referto a pair of relatively ro-Q tatable members in the respective forms ofa drum and of' a sleeve surrounding the drum.

The sleeve 21 is separated from the drum 20 by av clearance space 23.The clearance between drum and. sleeve is selected to permit freerelative rotation of thesemembers while, at the same time, limiting,insofar as is practicable, the flow of fluid in the clearance space.

Other elements of the apparatus include a fluid-receiving groove 26 ofany suitable cross section, a reaction block 27 seated in the groove toobstruct or impel flow of fiuid therein, a high pressure port 28 openinginto the groove 26 on one side of the block 27, a low pressure portmovement which is transverse to the said relative move-y.- meat, butwhich may be axial or radial or part axial and part radial. The firsthalf of this transverse movement momentarily displaces the vane 39 awayfrom its normal groove-obstructing position so as to clear the reactionblock 27. The second half of the transverse movement returns the vane 30to its groove-obstruction position after the vane has passed by thereaction block. A means suitable to produce such. transverse movement ofthe vane is not shown in FIGS. 1 and 2. However, an example of suchmeans will be later described.

Each of the elements in FIGS.- 1 and 2 may be one of several. Theconsidered apparatus may include separately, or in any combinationthereof, any one or more of the features of one or more annularfluidreceiving grooves, one or more reaction blocks in each groove, andany suitable number of vanes, of which one, some or all may operateeither in only one groove or in more than one groove.

If thereis more than one groove, the grooves may have differing depthsand/or widths, i.e. be of dilferent cross section. The transversemovement of the one or more vanes may be reciprocating, twisting, oroscillatory in character.

In the form of apparatus shown in FIGS. 1 and 2, the sleeve 21 isstationary, the drum is rotatable about its axis, the annular groove 26is formed in the drum 20, the ports 28 and 29 communicate with thegroove 26 through the sleeve 21, the reaction block 27 is coupled inangularly fixed relation with the sleeve 21 to be stationary, and thevane 30 is coupled in angularly fixed relation with the drum 20 torotate therewith. However, the present invention extends to other formsof apparatus. For example, the drum may be stationary and the sleeverotatable, in which case the high and low pressure ports will passthrough the stationary drum. While the block 27 and the vane 30 arealways coupled with opposite ones of the members 20, 21, the block 27may be coupled to the drum instead of the sleeve, and the vane 30 may becorrespondingly coupled to the sleeve instead of the drum. The block 27may be coupled to either the rotating or the non-rotating one of themembers of the drum-sleeve combination. The transverse movementundergone by the vane to pass by the block is in the nature of arelative movement between block and vane, and hence may be producedeither, as described, by having the vane transversely movable and theblock transversely stationary in an absolute sense, or by having thevane transversely stationary and the block and groove transverselymovable, or by having both the vane transversely movable and the blockand groove transversely movable. As stated the mentioned transversemovement maybe either radially directed or axially directed or partaxially and part radially directed, i.e. be. a motion which isresolvable into axial and radial components.

The apparatus shown in FIGS. 1 and 2 operates as follows as a motor.Gaseous or liquid fluid is introduced into and exhausted'from theapparatus at relatively higher and lower'pressures by Way of the highand low pressure ports 28 and 29 which in this instance act respectivelyas the inlet port and as the outlet port. The high pressure fluid isrepresented in FIGS. 1 and 2 by stippling. This high pressure fluidflows from the inlet port '28 into a working chamber whose boundingwalls are formed by the annular groove 26, the portion of sleeve 21which covers the groove, the reaction block 27, and the vane 30. Sincethe reaction block 27 is stationary and exerts a reactive force on thefluid, the fluid cannot flow angularly' in the groove in the clockwisedirection. However, since the vane 30'is movable, and since the pressureof the fluid exerts a force on the vane, the vane will be drivencounter-clockwise by the fluid. This counter-clockwise rotation of vane30 is' represented in FIG. 2 by the arrow As the vane 30 movescounter-clockwise, it causes exhaustion through the outlet port 29 ofresidual fluid in the. chamber 40 which is bounded by the groove andsleeve and by the surfaces of the reaction block and vane which areangularly opposite the surfaces thereof which bound the working chamber35. The vane 30 continues to be driven by the fluid in the workingchamber 35 until the vane comes into angular registration with theoutlet port 29. Thereupon, the fluid in the working chamber exhauststhrough the port 29.

Meanwhile, the vane is carried towards the reaction block by the angularmomentum of the drum. As the vane approaches the block, the vane iscaused to undergo (by means not shown in FIGS. '1 and 2) a first motionwhich displaces the vane transversely to a position where the vane willclear the block. When the vane has passed the block, it undergoes asecond transverse motion which returns it to the normal position whereinthe vane obstructs the groove. A the vane now moves away from thereaction block, the space opening in the groove between the block andvane is a space which. provides a new working chamber for the highpressure fluid from inlet port 28. This high pressure fluid is receivedinto the new working chamber, and the described cycle begins all overagain.

The operation just described is the operation of a fluid motor becausethe apparatus is supplied with an input of fluid energy, this fluidenergy is made available by a drop in the pressure of the fluid as itpasses through the apparatus, and the apparatus translates suchavailable fluid energy into mechanical energy which is manifested by therotation of drum 20, and which may be extracted from the apparatus as anoutput thereof. Obviously, however, the described apparatus is alsoadapted to operate as a fluid pump either by reversing the high and lowpressure fluid connections thereto, or by reversing the direction ofrotation of the drum. When operating as a pump by virtue of a reversalin the direction of drum rotation, the ports 28 and 29 are connected asbefore to communicate respectively with high and low pressure points ofthe fluid system, but the low pressure port 29 becomes. the inlet port,the high pressure port 28 becomes the outlet port, the direction ofrotation of drum 20 is reversed, and an input of mechanical energy issupplied to rotate drum 2%) and vane 30. Under such circumstances, thefluid will. flow through the apparatus from port 29 to port 28. Also,the input, of mechanical energy will be translated into increased fluidenergy which is manifested by the increased pressure of the fluid at theoutlet port28 as compared to the pressure thereof at the inlet port 29.

It will be. noted that the described apparatus when operating as a motoris bidirectional in the sense that the drum can equally well be rotatedin either direction simply by reversing the fluid connections thereof tothe external fluid system so that port 29 becomesthe high.

pressure port and port 28 the low pressure port. Similarly the describedapparatus when operating as a pump is bidirectional in' that byreversing the fluid connections and, also, the direction of rotation ofthe drum, the direction in which the fluid is pumped can be reversed.

For proper operation, the apparatus of FIGS. 1 and 2 should have in thehigh pressure line a check. valve to prevent a short circuit for fluidfrom the high pressure port around groove 26 and to the low pressureport at the time vane 30 is passing block 27. Such apparatus should alsohave a check valve in the low pressure line in order to avoid therein amomentary reversal (due to back pressure) of the direction of fluid flowduring the time vane 30 is passing block 27 As later described infurther detail, the need for such check valves or similar accessories isobviated by employing at least two vanes per reaction block.

Rotary motion, aligned impulsion apparatus of the sort described isgenerally known to the art. Such prior art apparatus is, however,subject to numerous disadvantages, among which may be mentionedexcessive friction and binding between parts, excessive wear of suchparts, and excessive vibration. The defects just mentioned are causedprimarily by the action on various parts in the machine of forces whichare neither balanced, minimized to the practical limit, nor effectivelycounteracted. Such forces, in general, will vary directly with thepressure of the fluid in the machine or directly with the square of thespeed of operation of the machine or directly with both.

When the operating pressure is relatively low, and, also, when the speedof operation is relatively low, the machine known to the prior art willbe characterized by wear, friction and vibration to an extent which isundesirable. When the fluid pressure and/or the speed of operation arehigh, the prior art machines will be characterized by wear, friction andvibration to an extent which renders impractical the use of suchmachines in high pressure, high-speed applications.

It is accordingly an object of the invention to provide rotary motion,aligned impulsion apparatus in which the above mentioned disadvantagesof friction, wear and vibration are minimized under all pressure and/orspeed conditions.

Another object of the invention is to provide apparatus of the statedsort which is well adapted for use in high speed, high pressureapplications thereof.

A further object of the invention is to alleviate in rotary motionaligned impulsion apparatus the deleterious effects on one or more vanesthereof of unbalanced forces to which such one or more vanes may besubjected.

A further object of the invention is to minimize lateral deformation ofany vane while it is in transverse motion.

A further object of the invention is to minimize the force required toimpart transverse motion to any vane.

These and other objects are realized according to the invention asfollows.

From the prior discussion it is evident that one or more vanes of theapparatus are driven transversely by a camming means or equivalent meansand the vanes are guided in their transverse motion by being receivedwithin slots formed in the member (drum or sleeve) with which the vanesare coupled.

If the driven ends of the vanes were to project beyond the slots of suchmember, such ends would be laterally deflected by forces exerted thereonby the camming means or equivalent in a direction at an angle to thevane axis, and such lateral deflection would tend to cause jamming ofthe vanes in their slots. This difliculty is overcome according to theinvention by forming in the member (at the end thereof where the vanesare driven) a channel or other recess which extends transversely intothe member and which transects all the vane-receiving slots. The cammingmeans or its equivalent is shaped to project transversely into suchchannel or recess to there exert its driving force upon each vane. Inthis way all vanes are fully supported by the sides of the slots inwhich they are received during the entirety of the transverse motion ofthe vanes.

For a better understanding of the invention, reference is made to thefollowing description, the already described FIGS. 1 and 2 of thedrawings, and to the remaining figures of the drawings.

FIGS. 3 and 4 will first be considered. In the embodiment shown in thosefigures, a stationary bushing 40 is disposed within a cylindricalhousing 41 for the apparatus. The inside surface of the bore of thecasing and the outside surface of the bushing may have matching slightconical tapers to assure good metal contact between housing and bushingwhen the latter is axially advanced under pressure into the bore of theformer. The axial position of bushing 40 within housing 41 may beadjusted by appropriate rotation of set screws 41a, of which each isthreadedly received within a passage 41b, such passage being formed atthe interface of housing and bushing so that the circular bore of thepassage is provided half by the housing and half by the bushing.

The bushing 40 surrounds and acts as a sleeve for a rotatable drum 42which is separated from the bushing by an annular, axially extendingclearance space 43. The inside surface of the bushing and the outsidesurface of the drum have matching slight conical tapers permittingadjustment of the amount of clearance therebetween by relative axialadjustment of the drum and the bushing. The clearance between drum andbushing is made as small as is consistent with free rotation of theformer within the latter to thereby reduce to a minimum the leakage offluid through the clearance space.

The cylindrical drum 42 is mounted by a spline coupling 44 on a shaft 45(FIG. 4) which is mounted for free rotation within the housing 41 by apair of axially separated bearing assemblies 46 and 47. At its righthandend the shaft 45 passes out of the housing through a gland 48 adapted toact as a fluid seal. At its lefthand end the shaft terminates short ofan end plate 49 which closes off this end of the apparatus. Between thisend plate 49 and the adjacent end of shaft 45 there is a space 49defining a reservoir for collecting fluid which may find its way throughthe space 43 or through the (soon to be described) slots which areformed in the drum 42. In order to equalize fluid pressure at oppositeends of the machine, an axial channel 45' and connecting radial conduits44' are formed in the shaft 45. In this way, an axial balance isobtained of the fluid pressure forces acting on the drum 42 and on the(soon to be described) vanes which are received within the slots in thedrum. A central aperture 50 in the end plate 49 permits drainage fromthe apparatus of fluid which has leaked away from the operating zonethereof.

.Such operating zone is provided by a set of annular groves 55, a, 55b,550 which are axially of rectangular cross section, and which are formedas a series of axially spaced recesses in the drum 42. Within each suchgroove are seated in radially opposed relation a pair of reactionblocks. Thus, for example, the groove 55 contains the radially opposedreaction blocks 56 (FIG. 3) and 57. Of the reaction block pairscontained in, respectively, the other grooves 55a, 55b, 550, the bottomblocks 57a, 57b and 57c are shown in FIG. 4. In the four grooves, thefour bottom reaction blocks are mutually aligned to be bisected by thesame vertical plane, while, similarly, the four top reaction blocks aremutually aligned to be bisected by that plane.

The reaction blocks 56 and 57 are maintained in axially fixed relationwith the bushing 40 by the pins 5 8 and 59 (FIG. 3). Similar pins areemployed to couple the other reaction blocks in angularly fixed relationwith the bushing 40. As shown in FIG. 4, the heads of the four pins forthe four bottom reaction blocks are recessed within a slot-likedepression 60 formed in the bushing 40. The heads of the pins for thefour top reaction blocks are recessed within bushing 40 in a similarmanner (not shown).

A further description will later be given of the details of constructionof the reaction blocks themselves and of the anchoring means for suchreaction blocks.

In addition to the four mentioned grooves 55, 55a,

55b, 550, there is formed within drum- 42 eight axial slots (FIG. 3)disposed at 45 angular intervals about the drum. The slots 65 axiallytransect the four mentioned grooves and are radially cut into the drumdeeper than are those grooves. to be axially slidable therein are acorresponding number of vanes 66. As shown in FIG. 4 each vane 66 hastwo axially separated end portions 67, 68 and, between those endportions, a series of axially spaced central portions of reduced radialsize. Those central portions are created in each vane by a series ofrectangular recesses or notches 70, 70a, 70b, 70c which extend into thevane in the radial direction from the margin 71 of the vane which isnearest to the clearance space 43 between the drum 42 and the bushing40. The mentioned notches correspond to, respectively, the grooves 55,55a, 55b, 550. Each notch has an axial and radial extent suitable tocontain with clearance either Received within the slots 65 of thereaction blocks within the corresponding groove when the vane is axiallyshiftedrightward from its working position shown in FIG. 4 to theblock-passing position for the vane. When a vane is fully inblock-passing position, the vertical center line of each of its notches70, 70a, 70b, 70c coincides with the vertical center line of thecorresponding groove formed in the drum 42. Therefore, when a vane is soaxially shifted to its blockpassing position, the vane is adapted topass by either all the top reaction blocks or all the bottom reactionblocks as the rotation of the drum 42, causes the vanes to moveangularly relative to the reaction blocks.

As stated, the position which is shown for the vane 66 appearing in FIG.4 is the working position for that vane. The vanes 66 are so constructedthat, when any such vane is disposed in its working position, a solidportion of the vane extends across each of grooves 55, 55a, 55b, 550 tothereby render all grooves obstructed by the vane. Thus, any vane 66 inWorking position will obstruct the angular flow of fluid in all grooveswhen the described machine is operated as a motor or, alternatively,will impel the flow of fluid in all grooves when the machine is operatedas a pump.

For the purpose of reciprocating each vane 66 back and forth between theworking position at which it obstructs the four grooves and the positionat which the vane passes by the reaction blocks in the grooves, eachvane 66 is provided at opposite ends with the cam follower faces 75 and76. The lefthand follower face 75 (FIG. 4) is driven by the cammingsurface 77 of a cam sleeve 78 inserted into the lefthand end of themachine between the bushing 40 and the end plate 49 and bearing assembly46. Similarly, the righthand cam. follower surface 76 of vane 66 isdriven by the camming surface 79 of a cam sleeve 80 inserted into therighthand end of the machine between the bushing 40 and the gland 48.The cam sleeves 78 and '80 are adjustable in axial position relative tobushing 40 by the rotation of set screws 81 received threadedly withinpassages 82 formed at the interface between the bushing and each camsleeve, the circular bore of each such passage being thereby providedhalf by the bushing and half by the associated cam sleeve. The mentionedcam sleeves may be so axially adjusted from time to time in order totake up play between the camming surfaces 77, 79 of the sleeves and thecam follower faces 75, 76 of the vanes.

Pressure from a fluid system (not shown) is manifested within thedescribed machine in a manifold 85 which is the high pressure manifold(or alternatively may be the low pressure manifold) and in a manifold 86which is the low pressure manifold (or, alternatively, may be the highpressure manifold). Both manifolds are in the shape of annular chambersformed between the housing 41 and bushing 40. The manifold 85 is influid corn,-

munication with a pair of radially opposed fluid distribution conduits87, 88 which are of arcuate form as seen in cross section (FIG. 3), andwhich (FIG. 4) each extend axially and to the right of manifold 85between the housing 41 and the bushing 40. Arcuate fins 85a, 85b act asbafiies between manifold 85 and, respectively, the conduits 87 and 88.Of those conduits the former communicates with a series of high pressureports 89, 89a, 89b, 89c opening into, respectively, the grooves 55, 55a,55b, 550. The latter conduit 88 communicates with a series of highpressure ports of which only port 90 is shown (FIG. 3) but which openinto the same grooves in radially opposed relation to the first-namedhigh pressure ports.

The manifold 86 is in fluid communication with a pair of radiallyopposed fluid distribution conduits 91 and 92 which are of arcuate formas seen in cross section (FIG. 3). Arcuate fins 86a and 86b act asbaflies between the manifold 86 and, respectively, the conduits 91 and92-. Of the conduits 91, 92 the former communicates with a series of lowpressure ports of which only the port 93 is shown (FIG. 3) but whichopen into, respectively, the grooves 55, 55a, 55b, 550. The latterconduit 92 opens into a series of low pressure ports of which only port94 is shown (FIG. 3) but which open into the game grooves in radiallyopposed relation to the first named low pressure ports.

As shown in FIG. 3, around the groove 55, the distribution of ports issuch that high pressure ports alternate with low pressure ports.Furthermore, the ports are distributed in relation to the reaction blockunits 56, 57 in groove 55 so that each reaction block unit has one highpressure port and one low pressure port on opposite sides thereof withthe nearer edges of the ports extending substantially up to the centralor block proper section of the reaction block. The distribution whichcharacterizes the port openings into groove 55 is a distribution whichis repeated for the three groups of four ports which open into,respectively, the other three grooves 55a, 55b and 550 of the drum 42.Thus, if each of grooves 55a, 55b, 55c is viewed in the same directionas that which yields the cross section of groove 55 which is shown inFIG. 3, each of grooves 55a, 55b and 550 will be like groove 55 in thatthe top reaction block will be flanked on the right by a high pressureport and on the left by a low pressure port, and in that the bottomreaction block will be flanked on the right by a low pressure port andon the left by a high pressure port.

The group of axially spaced, angularly aligned ports 89, 89a, 89b and890 are separated from each other by arcuate ribs 83 which are formed inthe bushing by the radial passage therethrough of the port openings.Each such passage is characterized by an axial cross section whichresembles a funnel in that slanting chamfer walls 84a taper the crosssection from a wide mouth at its radially outward end to a neck at theradially inward end of the passage and formed by vertical walls 84bwhich bound the passage. Such chamfer walls 84a and vertical walls 84bare shown for port opening 89 in, FIG. 4.

Inasmuch as in the considered embodiment the grooves 55, a, 55b, 55c andtheir respectively associated reaction blocks, ports and so on are allsubstantially identical in structure and operation from groove togroove, the description hereinafter will be confined to the groove 55and to its associated components. It is to be understood, however, thatunless the context otherwise requires, such description applies as wellas to the other grooves and to their associated reaction blocks, portand the like.

FIG. 5 is a developed view of the angular interval around the bushing 40which includes the reaction block 56 in groove 55, the ports 89 and 93which open into this groove, and the portions of the camming surfaces 77and 79' which extend over this angular interval. While the view in FIG.5 is limited to the angular interval mentioned, the figure is generallyillustrative of the space relations obtaining between each reactionblock, the associated high and low pressure ports, and the angularlycorresponding portions of the camming surfaces.

As shown in FIG. 5, the camming surfaces 77 and 79 are from right toleft divided into a dwell section 100, a camming section 101 extendingleftward to the axial center line 102 of reaction block 56-, anothercamming section 103 symmetric with cam section 101 about the center line102 and extending leftward from that center line, and another dwellsection 104. For reasons later explained, the shown earn sections 101,103 each extend at both ends beyond the angular intervals occupied bythe correspond ing ports 89 and 93.

The shown. dwell and cam sections of the camming surfaces are adapted tocontrol as follows the axial position of a vane which is rotating to berepresented by a movement from right to left in the developed view ofFIG. 5. When the vane is angularly positioned in the dwell section 100,the camming surfaces 77 and 79 maintain the vane axially disposed at thenormal position thereof in which a solid portion of the vane obstructsthe groove 55 in the drum 42. For this normal working position of thevane, the vane is transversely stationary and the camming surfaces liein planes which are normal to the axis of the mentioned drum. As thevane moves into the cam section 101, the shown curvatures of the cammingsurfaces 77 and 79 impart to the vane an axial motion which displacesthe vane away from its normal axial position and which is to the rightas' seen in FIG. 4. The amount of rightward displacement of the vaneover camming interval 101 is sufficient to permit the reaction blockunit 56 to pass with clearance through the notch 70 in the vane. Hence,in the course of its angular movement, the vane will freely pass by thereaction block.

As the vane in its angular movement makes the transition from camminginterval 101 to camming interval 103, the axial motion of the vanechanges from a motion of displacement to a motion of replacement whichresults at the end of the camming interval 163 in a return of the vaneto its working position. The vane remains in this last-named positionover the angular interval represented by the dwell section 104, anduntil such time as the vane is again given a new axial motion for thepurpose of clearing the reaction block unit 57 which, as shown in 1526.3, is displaced by 180 from the reaction block unit The cammingsurfaces, in order to reciprocate the vanes, must contact the vanes toimpart accelerating and decelerating forces thereto. Over a period oftime such forces and the motions of the vanes will tend to producesubstantial wear on the camming surfaces, and, also, on the vanes.Applicant has found, however, that this wear can be minimized by havingthe camming intervals of the camming surfaces conform to a curve forwhich, mathematically speaking, the first derivative is zero and, also,the second derivative is zero at both of the two points on the curvewhich respectively correspond to the beginning and end of the cammingintervals. A curve having such slope characteristics can be readilyderived by mathematical procedures known to the art.

From the description already given of the generalized form of apparatusshown in FIGS. 1 and 2, and from the foregoing description of thepractical embodiment shown in FIGS. 3 and 4, the operation of the FIG. 3and 4 embodiment should be obvious. If the vanes 66 are impelled byfluid which enters by the high pressure manifold 85 and leaves by thelow pressure manifold 86, the drum 42 will rotate clockwise as seen inFIG. 3, and the apparatus will act as a motor. If, on the other hand,the vanes 66 impel fluid which enters by low pressure manifold 86 andwhich leaves by high pressure manifold 85, the drum 42 will be rotatedcounterclockwise, as seen in FIG. 3, to provide this impulsion action,and the app-aratus will operate as a fluid pump. The apparatus can alsobe converted from a motorto a pump by employing the same clockwisedirection of rotation as before of the drum but by reversing the fluidconnections to manifolds 85 and 86 so that 85 becomes the low pressuremanifold and 36 becomes the high pressure manifold.

As stated heretofore, one of the troublesome problems encountered inapparatus of the sort described is the problem of balancing or otherwisecounteracting the fluid pressure forces which act on various mechanicalparts.

Ideally, such balance or counteraction should be attained in all threeof the angular, radial and axial directions which characterize themachine. For a better understanding of what is meant by such balance orcounter action in all three direction, reference is made to 'FIG. 6which shows in schematic form one of the vanes 66 of the describedapparatus. As indicated by this figure, the represented vane 66 issubjected to leftwardly and rightwardly directed angular forces,represented by the arrows 10 110, 111; to upwardly and downwardlydirected radial forces represented by the arrows 112, 113; and toleftwardly and rightwardly directed axial forces represented by thearrows 114, 115 for rightward forces, and by the arrows 116, 117 forleftward forces. Most of these forces are created by the pressure of thefluid in the apparatus. Consideration will now be given to the variousways in which the described apparatus balances or otherwise neutralizesthose fluid pressure forces.

In the embodiment of FIGS. 3 and 4, the pressure of the fluid will actin axially opposite directions on the two side walls 118 and 119 (FIG.4) of the groove 55 which is formed in the drum 42. Also, the pressureof the fluid will act with equal force in axially opposite directions onthe two side walls of the recess '70 which is formed in the vane 66. Thebalance of forces on the remote end margins of the vanes by means of thechannel 45 and the passage 44' has been previously referred to.Therefore, both the drum 42 and the vanes 66 will be axially balanced inrespect to fiuid pressure forces.

Referring to FIG. 3, the difference in value between the pressure of thefluid at high pressure ports 89, 9t} and at low pressure ports 93, 94 isa pressure difference which could produce serious radial unbalance ofthe machine and of the rotatable member. For example, such seriousradial unbalance would exist if there were present only one highpressure port and only one low pressure port. In the shown embodiment,however, this particular problem is overcome by providing at least twohigh pressure port which are located at equally spaced angularintervals, at least two low pressure ports whtich are also located atequally spaced angular intervals, and at least two reaction blocks whichare seated at equally spaced angular intervals in the groove. By soproviding equally spaced high pressure ports and equally spaced lowpressure ports, the radial fluid pressure forces at the high pressureports act equally and oppositely to cancel each other out. Similarly,the radial pressure forces at the low pressure ports act equally andoppositely to cancel each other out. Therefore, insofar as the ports areconcerned, the machine and rotatable member are both balanced in respectto radial pressure forces.

In general this radial balance in respect to the ports may be securedfor any number of paired inlet and outlet ports exceeding two pairs byfollowing the technique of distributing the inlet ports at equal angularintervals about the groove, and by distributing the outlet ports atequal intervals about the groove in alternation with the' about thegroove and by also distributing the three outlet ports at 120 intervalsabout the groove in alternation with the inlet ports. When the inlet andoutlet ports are so distributed, radial balance is obtained at the rotorin respect to the fluid pressure forces at the ports because.

of the fact that such forces will act on the rotor with respectivemagnitudes and directions in the radial plane to satisfy the equationsfor static equilibrium of the rotor in the radial plane. In other words,the algebraic vector sum of all such forces on the rotor in the radialplane will be zero, and the algebraic sum of all moments on the rotor inthe radial plane will also be equal to zero.

Where two or more inlet ports and two Or more outlet ports communicatewith a common groove, it is necessary, to attain radial balance, for theassociated reaction blocks to be seated in equally spaced angularrelation in such groove. Furthermore, under such circumstances, it isnecessary to have equiangularly distributed vanes of a number which (forreasons later explained) is preferably more than twice the number ofreaction blocks. This is shown in FIG. 3, wherein the eight shown vanesare equiangularly distributed, and are four times the number of the tworeaction blocks 56, 57. With the conditions just stated being met, anexcellent radial balance of the machine is obtained.

In the apparatus, the vanes 66 are subjected to a fluid pressure forcewhich acts in the radially inward direction. This force tends to pressthe vanes against the bottoms of the axial slots 65 to thereby render itdifficult to reciprocate the vanes in the slots.

The problem just mentioned may be overcome in the presently describedapparatus by providing the following elements which are shown in FIG. 4;

(a) Apertures 120 passing radially through each vane 66 and axiallydisposed so that each aperture is at the center of a corresponding oneof the grooves 55, 55a, 55b, 550 when the vane is in working position;

(b) Cavities 121 formed in the bottom of each slot 65 directly belowgrooves 55, 55a, 55b, 55c, respectively, each cavity being axiallycoextensive with its correspond ing groove, and one of the apertures12!; opening into each cavity;

Passages 122 extending from the central notches of each vane 66 to thebottom margin of the vane such passages being provided, for example, byshallow, radial extending channels formed on both sides of the vanebelow the notches; and

(d) Recesses 123 formed in the bottom margin of each vane 66 directlybelow the notches thereof, each such recess being axially coextensivewith the corresponding notch and being in fluid communication with thechannel 122 extending radially inward from that notch.

The above-described combination of elements serves to equalize the fluidpressure forces which act upon the top and bottom of each vane. Theequalization of such forces eliminates much of the friction involved inmoving the vanes in their slots.

Instead of counteracting by equalization of fluid pressure forces thetendency of the radially inward fluid pressure force to lock the vanesin their slots, it is possible to counteract this tendency by providingball bearing mountings for the vanes. In connection, however, with suchtype of mounting (and with other types of mountings as well), therearises the problem which is illustrated in FIG. 7. In the schematicdiagram of this figure, a vane 66 is represented as being supportedabove the bottom of its slot 65 by the ball bearings 97 and 98, the vanebeing driven from left to right by the camming surface 77 of the camsleeve 78. To produce this driving action, the camming surface 77 exertson the vane 66 a force which, together with its center line of action,is indicated by the arrow F This driving force is opposed by two forces,namely, (a) a force which, together with its center line of action, isindicated by the arrow F and which is equal to the mass of vane 66 asmultiplied by its acceleration; and (b) a force which, together with itscenter line of action, is indicated by the arrow P and which is africtional force exerted by the bearings 97, 98 on the bottom of vane66. The resultant of forces P and F is a force which acts in theopposite direction to driving force F and which is equal in magnitudethereto, but which has a center line of action displaced radially inwardof the center line of action of the force P This radial displacementbetween driving force F and the resultant of forces P and F; produces onvane 66 a clockwise moment tending to cant the vane and thereby eitherforce the lefthand end of the vane against bushing 40 or, alternatively,force the righthand end of the vane (not shown) against the bottom ofslot 65. In other words, the described camming of the vane tends to lockthe vane against movement in its slot.

Another vane mounting problem is illustrated schematically 11 FIG. 8. Inthis last-named figure, the drum 42 is assumed to be rotating so as toproduce peripheral movement of the vane 66 in the direction indicated'bythe arrow 99. The camming surface 77 of cam sleeve 78 is inclinedrelative. to this direction of peripheral movement 12 so as to axiallydisplace the vane 66 from left to right within its slot 65. The drum 42,vane 66 and camming surface 77 have a relative disposition such that thelefthand end of vane 66 projects outwardly of the lefthand end of drum42 in order to make contact with the camming surface.

In this situation the inclination of camming surface 77 causes thissurface to exert on vane 66 a driving force F which is at an angle tothe axis of the vane, and which accordingly has a component F acting onthe lefthand end of the vane at right angles to its axis. Inasmuch asthe projecting portion of lefthand end of the vane is in the nature of acantilever beam in that no lateral support is provided for such portionexcept at its base, the effect of the action of the component F is toproduce a significant lateral deflection of the unsupported vaneportion. This lateral deflection will, when present, serve as anotherfactor tending to cause jamming of the vane against movement in itsslot.

The problems illustrated in FIGS. 7 and 8 are overcome by the vane andcam construction shown in FIGS. 9, 10 and 11. In this construction, apair of rounded grooves are formed on opposite sides of vane 66 toextend inwardly from its lefthand end face 75. A similar pair of grooves126 are formed on opposite sides of vane 66 to extend inwardly to itsrighthand end face 76. The center lines of all grooves coincide with theaxial line 127 which is the center line of mass for vane 66 in the sensethat the mass of the vane disposed radially outward of line 127 equalsthe mass of the vane disposed radially inward of that line. Because ofthe notches which are formed in vane 66, the center line 127 of massdoes not necessarily coincide with the vanes geometric center line,i.e., that line which lies halfway between the radially inward andoutward margins of the vane.

As shown in FIG. 10, the rounded grooves 126 in vane 66 are matched by apair of rounded grooves formed in the side walls of slot 65. Similarly,the grooves 125 of the vane are matched by rounded grooves (not shown)formed in the mentioned side walls of the slot. Each vane groove andeach matching slot groove form a guideway within which is received a setof ball bearings 129. The ball bearings are retained within suchguideway by pins 139 which pass crosswise through vane 66 to project onboth sides of the vane into the grooves on opposite sides thereof.

As will be noted from FIG. 10, the ball bearings 129 support vane 66 insuch a manner that the vane is held above the bottom of slot 65, it isalso held away from the side walls of the slot, and, further, isconstrained so as not to be removable from the slot by force applied inthe radially outward direction. Thus, the described ball bearingmounting for the vane has a number of advantages. For example, themounting precludes the generation of a large'frictional drag opposingaxial motion of the vane and due to the pressing of the vane against thebottom of its slot by fluid pressure force acting radially inwardly onthe top margin of the vane. Furthermore, inasmuch as the mounting holdsthe vane away from the sides of its slot to thereby maintain sidewiseclearance at all times between vane and slot, the mounting precludes thedevelopment of friction force opposing axial motion of the vane andarising out of a pressing of the vane against one side of the slot as aresult of an unbalance of the fluid pressure forces acting on oppositesides of the vane. Still further, in the instance where the describedmachine is run at high speed, the ball bearing mounting of FIG. 9precludes the throwing of a vane out of its slot by centrifugal force.

In the construction shown in FIGS. 9 and 11, the vane 66 is contacted bythe camming surfaces 77, 79 in the following manner. The drum 42 hasformed therein, at its lefthand and righthand ends, respectively, a pairof angular channels 131 and 132 of rectangular cross section whichextend axially into the drum from those ends.

The channels 131 and 132 transect all of the slots 65 which are formedin the drum. The cam sleeve 78 thus formed at its righthand extrernityan annular flange 133 which projects axially into channel 131 so as todispose all points on the camming surface 77 within that channel.Similarly, the cam sleeve 80 has formed at its lefthand extremity anannular flange 134 which projects axially into channel 132 so as todispose all points on the camming surf-ace 79 within that last-namedchannel. Because the camming surfaces 77 and 79 are both insheathed bythe dru-mthroughout their entire peripheries, there is no time duringthe cycle of axial reciprocation of the vane in which a portion of thevane projects beyond its slot 65. Hence, all portions of the vanereceive lateral support at all times and there cannot occur theundesirable cantilever deflection which is illustrated by FIG. 8.

Besides being axially located within channels 131,132. of the drum 42,the cumming surfaces 77 and 79 are radially located in relation to thevane 66 in such manner that the driving forces F exerted by thosesurfaces have center lines 135, 136 which coincide with and areextensions of the center line of mass 127 of the vane 66. Because ofthis coincidence and because, as described, the ball bearings 129 whichmount vane 66 are disposed along the common center line for the drivingforces and for the vane mass, there is no tendency for the vane tobecome canted in its slot as the vane is driven back and forth by thecams. eliminates the problem discussed in connection with FIG. 7.

In respect to pressure fluid forces which act in an angular direction onthe vanes, such forces will always be unbalanced when the vanes arebeing effective to provide a motor action or a pumping action. This isso, since, when the described apparatus is being used as a motor, it isthe presence of this unbalance which drives the vanes, and, since, whenthe apparatus is being used as a pump, the action of the vanes willproduce this unbalance of angularly acting forces. ,Therefore, anunbalance of angular forces on the vanes is, in fact, desirable so longas the vanes remain stationary in their groove obstructing or workingposition. When, however, any vane is disposed in those angular intervalsof its angular movement in which the vane is given either one of thereciprocal axial motions which displace the vane from its normal workingposition to its block-passing position to its normal working position,it has been considered hitherto that an unbalance of angularly directedfluid pressure forces becomes undesirable. The reasoning behind thisopinion which has been held is that any such unbalance tends to pressthe vane against one of the walls of its containing slot to thereby makeit more difficult to reciprocate the vane in the slot. However, as laterexplained in further detail, I have found that despite thisconsideration, a considerable improvement in capacity or horsepower canbe obtained by extending the camming sections of the camming surfaces tooccupy an angular interval greater than that over which a vane isangularly balanced in respect to fluid pressure forces.

FIG. 12 shows another problem which has been overcome in the presentlydescribed apparatus, As a vane 66 reciprocates back and forth in itsslot in order to pass by a reaction block, there isa tendency for fluidto be trapped in the space between the block and one of theside walls137, 138 of the rectangular recess 70 in the vane. In FIG. 12, thistrapped condition of the fluid is shown in the instance where the vane66 is in the course of passing by the block 56, the vane has juststarted to undergo the axial movement to the left which will return thevane from block-passing position to its normal working position, andfluid is present in the space 144 between the righthand wall 138 of therecess 70 and the righthand surface of the block. It is evident that thepresence of this fluid in the mentioned space creates an obstruction tothe fast return of the vane 66 to working'position.

Hence, the construction shown in FIG. 9

The difficulty just mentioned can be avoided by forming the recess 70 invane 66 to extend radially inward of the bottom of the angular groove 55which is formed in the drum 42. Since the bottom of the reaction block56 cannot be disposed any further inward than the bottom of groove 55,the radial deepening of the recess 70 creates within slot 65 an axiallyrunning passageway between it e bottom of the reaction block and theradially inward margin of recess 76. This passageway permits flow offluid in substantial amount from one side to the other of the reactionblock. Accordingly, as the vane 66 moves to the left in the course ofreturning from its blockpassing position to its normal working position,the fluid in the diminishing space to the right of block 56 is fluidwhich can freely flow out of this righthand space, through the mentionedpassageway, and into the space which is opening to the left of block 56between the lefthand surface thereof and the receding lefthand wall ofthe recess 70. Obviously, when the vane 66 is moving to the right in thecourse of going from its normal working position to its block-passingposition, the fluid in the space to the left of block 56 can likewiseflow through the mentioned passageway and around to the space which inthat instance will be opening to the right of the block 56.

It will be appreciated that other means may be em ployed to avoid fluidtrapping, as, say, one or more apertures formed in the reaction block topass axially therethrough. Such apertures will be later described.

FIGS. 13 and 14 show details of the reaction blocks used in thedescribed apparatus, and of the mode of coupling those reaction blocksto the bushing 40. As indicated by those figures, the reaction block 56is anchored to the bushing 49 by the pin 53 which passes through anaperture in the bushing and into an axial slot 146 which is formed inthe block. The pin thereby couples the block in angularly fixed relationwith the bushing. At the same time, relative axial movement can takeplace between the pin and the axial slot 146 in which the pin rides.Hence, the reaction block 56 is adapted to move axially to therebyadjust itself to a shift in the axial position of the groove 55 relativeto the bushing 40. This relative shift in axial position between grooveand bushing is likely to take place in small amounts over a period oftime because of wear induced in the described apparatus during continuedoperation thereof. Also, irrespective of wear, some shift may take placein operation because in differences in thermal expansion of variousparts of the machine.

While the described pin and slot coupling provides the desired effect ofself adjustment of the reaction block to slight shifts in axial positionof the groove 55, an inevitable result of such type of coupling is thecreation of a certain amount of play in the seating of the block in thegroove 55. This play tends to get Worse as the groove and block wear.Also, the block is subjected to an unbalance of angularly directed fluidpressure forces in that a high pressure port is located on one side ofthe block, and a low pressure port is located on the other side thereof.These two factors of play in the mounting of the block and of anunbalance of the angular pressure forces thereon, are factors which, incombination, will tend to cant the block in the groove. However, suchcanting is prevented in the presently described apparatus by twowing-like projections 150 and 151 which extend outwardly from oppositesides of the reaction block proper and into the annular groove 55. Asshown in FIG. 14, the extensions 150 and 151 are arcuately curved to fitsnugly in the annular groove 55.

The extensions 150 and 151 are also shaped, as shown in FIG. 13, torespectively have the tapers 152, 153 on the sides thereof which wouldbe to the right in FIG. 4, and to respectively have the shoulders 154,155 on the sides thereof which would be to the left in this last-namedfigure. The advantages of each of these two shaped por- 15 tions of eachof the mentioned extensions will now be considered in turn.

The efliciency of operation of the described apparatus can be maximizedby minimizing the angular interval over which each vane is maintainedfully axially displaced from its normal working position for the purposeof allowing the vane to pass by a reaction block. The principle juststated is true for the reason that, any interval over which the vanesare fully displaced substracts from the angular intervals over which thevanes are cammed, and, as pointed out hereafter, the greatest efliciencyof operation can be obtained by making such camming intervals as long aspossible. If the described extensions of the reaction block had notapers, the vanes, in order to pass the block, would, in effect, have tobe maintained fully displaced from working position over the wholeangular interval occupied by the block and by its extensions. However,with the extensions being tapered as shown, the angular intervalsoccupied by the extensions are intervals which can and do overlap withthe angular intervals over which the vanes are in axial motion fromnormal working position to block-passing position and from block-passingposition back to working position. Hence, the combination of theextensions 15%, 151 and the tapers thereon is a combination whichenables the prevention of canting of the block with no substantialaccompanying loss in the efliciency of operation of the apparatus.

While the tapering, as described, of the extension 150, 151 solves onedifliculty, it creates another in that fluid 1n the groove 55 will actupon the tapered areas 152, 153 with an axially directed pressure force.This force, if unopposed, will create unwanted friction between theblock 56 and the wall 156 of the groove 55 towards which such axialpressure forces urge the block. Further, inasmuch as the axiallydirected pressure forces on tapered areas 152, 153 are unequal becauseof the fact that the block has high pressure and low pressure onopposite sides thereof, such forces if unopposed will produce on theblock a moment tending to rotate it around pin 58 and thereby jam theextension on the high pressure side of the block against the side ofgroove 55. Those lastnamed difficulties are, however, avoided in thedescribed apparatus by providing the shoulders 154, 155 which are formedin the extensions 150, 151 axially opposite the tapers 152, 153. Thepresence of such shoulders in the extensions 150, 151 create respectiveopen spaces between such extensions and the mentioned wall 156 of groove55. These open spaces receive fluid which is under pressure,

and which in such spaces exerts on the extensions 150, 151

an axially directed pressure force which is equal and opposite to theaxial pressure force exerted on the tapered areas 152, 153 of theextensions. In such circumstances, each extension will be balanced inrespect to axial fluid pressure forces, and the block 56 will not besubject to a moment and will not bear with undue force against the side156 of the groove 55.

If desired, the balance of axial pressures can be improved by forming inthe extensions 150, 151 respective apertures 157, 158 which axially passthrough the extensions between the shoulders thereof and the taperedsides thereof and by forming in the block proper 160 of the reactionblock unit an aperture 159 which axially passes from side to sidethrough the block proper 160. All those apertures will assist inprecluding trapping of fluid between a vane and the reaction block asthe vane reciprocates to pass by the block and to then return to workingposition. As a further measure to avoid fluid trapping, preferably thetapered surfaces 152, 153 of the extensions 150, 151 are curved to beaxially equidistant at all points from the camming surface 77. If thetapered surfaces are so curved, the separation between those surfacesand the adjacent vertical side of notch 70 of vane 66 is a separationwhich remains constant as the vane passes by the reaction block.

If desired, how.

ever, the tapered surfaces may be of any shape permitting clearancebetween the extension 150, 151 and the vane.

Corning now to the matter of improving the capacity as a pump of thedescribed machine, for any one groove the capacity C per block is givenby:

where h equals the groove width, w is depth and v is the peripheralvelocity of the vanes relative to the block.- The product hwv alsoexpresses horsepower per block per groove when the machine acts asv amotor. The peripheral velocity v is, of course, equal to the centroidalradius of the cross sectional area of the groove times the angularvelocity at that radius of the vanes relative to the block.

For fixed values of h, w and the centroidal radius of the groove,evidently the capacity C increase in proportion with v. However, vcannot be increased without limit. For an understanding of whatdetermines the maximum permissable value of v, reference is made toFIGS. 15A and 153 FIG. 15A illustrates schematically the camming section10 1 of the camming surface 79 (FIG. 5). For the purpose of FIG. 15A,the vane 66 is assumed to be moving from left to right with velocity v.As the vane so moves from origin 0 to the point where camming section101 joins dwell section 160, the vane is axially thrown in the ydirection by the distance H. The throw H in practice always exceedssomewhat the width 11 of the groove but theoretically can approach h.Hence, for analysis purposes, Expression (1) can be written in the form:

The cam section 101 occupies an interval a along the x axis betweenorigin 0 and the point of joinder with dwell section 100. This intervala will be assumed to be variable, the same assumption being made at alater time for the interval H. However, the profile of section 101 istreated herein as constant in the sense that the x, y coordinates of anypoint on this section will be the same for all values of a and H whenthe x coordinate is expressed as a percentage of a and the y coordinateis expressed as a percentage of H. Thus, for example, the x, ycoordinates for the shown point p will always be, say 0.35a, 0.20H,however, a and H may vary.

FIG. 15A shows for the camming section 101 a segment S which isreproduced in enlarged form in FIG. 15B. Referring to this last-namedfigure, the points 2 and p are points in S which are displaced fromorigin 0 by a fixed percentage of a as, say, 27% of a for p and 27.01%of a for p The horizontal interval g between p and p may be expressed ask a inasmuch as when a increases, g increases proportionately.

The segment S at points and 7 has, respectively, the slopes s and sThese slopes s and s may be equated to, respectively, the expressions k'H/ a and k' H/ a inasmuch as such slopes vary inversely with a anddirectly with H. Thus, for example, if a is doubled in value, each of sand s will be halved in value, but if H is doubled in value, s and swill likewise be doubled in value.

As vane 66 moves with peripheral velocity v over segment S to arrive atpoints p and at, respectively, the times t and t the axial or yvelocities of vane 66 at those points are given by the expressions:

However, (t -t equals g/v. Therefore y (S2VSlV)V S S V r 2 kaal) (I) y"=4 V /a (9) The force F exerted by segment S in the axial direction onvane 66 is equal to the constant mass of the vane, times theacceleration imparted thereto. In other Words However, the force F is acomponent of the force P exerted by segment S at any point thereon in adirection normal to the slope of the segment at that point. Thus, asshown at point p the forces P and F W form a right triangle having P forthe hypotenuse and F for one side thereof. This triangle is similar tothe right triangle at p which defines the slope s and which has thesides y yn or from 9 k' H and k a and, accordingly the hypotenuse Thelegs F and F of the force triangle correspond with the legs and k a ofthe similar slope triangle. Therefore:

Eiq 1 (alto and substituting the value for F expressed in 11 into 15,there is obtained:

Now, if (p is the angle at any point on s which exists between theforces P and 5,, at that point, and which is known as the pressure anglefor that point, it is the case that:

sec Ka (l8) and Expression 16 becomes:

F,. =I\ HI /a sec (,0 (19) I have found that the factor which ultimatelylimits the improvement in capacity or horsepower of the describedmachine is the stress set up in axially driving the vanes by the cammingsurfaces. In other words, no matter what changes are made in cam throwH, peripheral velocity v of the vanes or interval a of the cam- 18 mingsections, such changes must not result in producing a value for thementioned stress which exceeds a limiting value therefor, such limitingvalue being determined by, among other factors, the strength of thematerials used. I have also found that the value of the mentioned stressvaries directly with the force P Therefore, for any given machine thereis a maximum practical value F max for F the value F max being aconstant. This consideration leads to a rewriting of (19) as:

k HV /a sec gv F max (20) In (20), given that P max is a constant andassuming for the time being that H is constant, if sec (,0 is treated asa constant, then v can be increased at least linearly with an increasein a. This is so since if a is, say, doubled, then v can also be doubledwithout increasing the value of V /a whereby F max is not exceeded.However, from (2) it is evident that the capacity C of the machineincreases linearly with v. Therefore, the increase in a permits at leasta linear increase in capacity C.

As a matter of fact, with constant H an increase in a permits a morethan linear increase in v. This is so for the reason that by inspectionof (18) it will be seen that, as a increases in value, sec to decreasesin value to approach 1. However, from (20) it is evident that when secg0 decreases in value with increasing a, the decrease in sec q) permitsthe adding to the linear increase in v of an extra increase in v up tothe point where the lefthand side of (20) equals the righthand sidethereof. In order to determine how much extra increase in v can be addedto the linear increase in 11, sec (,0 is taken for that point of theentire camming section profile (FIG. 15A) where the pressure angle (,0is maximum.

It is also to be noted that when the peripheral velocity V is fixed, asit is in many applications, and that when H is treated as a variable andcan be increased while keeping the mass of the vane constant, anincrease in a permits increasing the capacity C of the machine almost asthe square of a. This follows from the fact that when in (20) the term Vis a constant and when sec q) is also treated as a constant, if a issay, doubled, the quantity H may be quadrupled without F max beingexceeded by the lefthand side of 20. However, if H is quadrupled, it isapparent from (2) that, to an approximation, the doubling of a producesa quadrupling of the capacity C.

Actually, the increase in C is affected by factors other than the squareof the increase in a. This is so for two reasons. First, as H isincreased, the value of sec increases somewhat, and, in order tocontinue to satisfy (20), this increase in sec to must be compensatedfor keeping H down to a value which is somewhat less than proportionalto the square of a as a increases. On the other hand, since the groovewidth 12 (which really determines capacity) may be less by a constantvalue than H as H increases, the factor increases percentagewisesomewhat faster than H to thereby tend to offset any loss in capacityattributable to the increase in sec 90. Therefore, in most instances thecapacity C can be increased almost as the square of a by increasing H tothe highest value thereof which will satisfy (20).

From the foregoing it is evident that it is highly advantageous toincrease the intervals a occupied by the camming sections of the cammingsurfaces of the described machine. Before, however, describing how thosecamming intervals are increased, according to the invention, it isnecessary to consider some of the factors which determine the length ofthose camming intervals.

Referring to FIG. 16, this figure is a schematic diagram of a rotarymotion aligned impulsion machine having the block proper portion liia ofa reaction block seated in a groove 166 formed in a clockwise rotatingdrum 167, two vanes 168a, 169a spaced in relation around the drum androtating therewith, a high pressure port 17% 19 on one side of the blockand a low pressure port 171a on the other side of the block. Thestructure of FIG. 16 is not a preferred embodiment inasmuch as there isonly one reaction block and, hence, the cross section of the machinethrough groove 166 is not radially balanced. However, the FIG. 16structure provides the best starting point for the ensuing discussion.

In the FIG. 16 machine, over a travel of 360 around the groove, eachvane goes through one complete operating cycle of working, axialdisplacement to pass the block and axial replacement to workingposition. Thus, in the FIG. 16 machine the vane operating cycle has avalue of 360. On the other hand in the FIG. 17 machine (which has twoblocks and four vanes) one complete vane operating cycle takes placeover 180 around the groove. From such considerations can be derived thegeneral rule that:

where D is the vane operating cycle angle and where B is the number ofblocks per groove.

It is desirable that, in the machines to which this invention relates,the angular extent of the ports be made as large as possible since, aslater explained, the angular intervals which can be devoted to cammingthe vanes are intervals which increase as the port angles increase. Thetwo possibilities for increasing the angular extent of a given portadjacent a given reaction block are (a) an increase in the directionaway from the block and (b) an increase in the direction towards theblock. Considering the former possibility, the edges 175a, 17611 ofports 170a and 171a are the far edges of such ports in relation to theblock 160a. Those edges coincide with the center lines of vanes 168a,169a when those vanes are in the position shown. In other words, theclosest angular interval by which the far edges of the ports 170a, 171aapproach each other is the inter-port angle i which for FIG. 16 is 180,the same as the angle of separation for this figure of the two vanes.This angle of separation sets a limit to the inter-port angle i since ifthe angle i is any less than the angle of separation, the high pressureport will be separated from the low pressure port around the angularinterval i by less than one vane thickness 2. when the vanes are in theposition shown. It follows that an interval i of less than the vaneangle of separation will result in excessive leakage or short circuitingof fluid around the interval i.

Inasmuch as the vanes are equiangularly distributed, the angle ofseparation between each two adjacent vanes of N total vanes is 36U/N. Ifthere are n vanes per block, the angle of separation is 360/nB. Asstated, in extending the ports away from block proper lfifia, theinter-port angle i between the extended port edges 175a, 176a should beno less than the vane angle of separation. Thus, the minimum value for iis given by:

i=360/nB 22 Formula 22 isa general formula as can be vertified byinspection of FIG. 17 wherein there are two blocks 165a, 165b, two vanesfor each block and wherein, as predicted by the formula, the angle ibetween the edges adjacent to each other of, respectively, the ports170a, 1711) are edges which are spaced by 90".

In connection with the foregoing discussion it is to be noted that theinter-port angle i is substantially coincident with the angular intervalover which each van is both subjected to a differential in the fluidpressure forces acting on opposite sides thereof and, at the same time,does useful work. For this reason the angle i may be considered as theworking angle or interval for each vane.

The angular interval left over in the vane operating cycle angle D aftersubtraction therefrom of the interport angle i will be referred to asthe non-working angle In. From (21) and (22) it is clear that:

m=360/B360/nB (23) or m=360/B(11/n) (24) The formula in 24 is again ageneral one. To demonstrate, if B equals 2 and n equals 2, the formulapredicts a non-working angle In of This value characterizes thenon-working angle m in each of the two 180 vane operating cycle angles Dfor the machine of FIG. 17 wherein there are two blocks and two vanesfor each block.

Considering now the possibility of increasing the angular extents ofeach port in the direction of the reaction block adjacent thereto, theedge of that port which is near the reaction block can be brought intoregistry with the block proper, i.e., that part of the block which (except for clearance) occupies the entire axial dimension of the groove inwhich it is seated. Beyond this, the angular extent of the port in thisdirection can be increased only by decreasing the angular interval boccupied by the block proper. The optimum value for this interval istwice the thickness 1 of the individual vanes where t is expressed indegrees. The reason why 2t is the optimum value for b is that such valueequalizes the leakage in the angular direction of fluid past the blockwith the fluid leakage in the angular direction past each vane when inworking position. To wit, fluid leaks past each vane through theinterface between the vane and the bushing, such vane leakage beingroughly proportional to t. However, fluid can leak past the block properboth through the interface between block proper and housing and throughthe interface between block proper and the bottom of the groove, theleakage past the block thus being twice that of the leakage past a vanefor the same angular thickness of both elements. It follows that bymaking the angular thickness of the block proper equal to twice that ofeach vane, the fluid leakage past the two elements will, roughlyspeaking, be equalized.

In instances where the mounting of the block is of a type permittingself-adjustment of the block in axial posi tion, the heretoforedescribed play in the block and the resultant possibility of canting ofthe block by the unequal pressures on its opposite sides are factorswhich would ordinarily render it impossible to reduce the thickness ofthe block proper to a value of 2t. However, I have found that byproviding the described winged extensions, I can overcome thisdifficulty associated with an axially self-adjusting block so that theangular thickness of the block proper can without difficulty be reducedto a value of 21 or less.

From the relationship which obtains in FIG. 16 between the non-workingangle m, the block angle 1; and the angular interval of each port, andfrom the expression for m which is given by (24), it is clear that whenthe block angle b equals 21, the maximum angle q for each port is givenby the general formula:

It is desirable to so maximize the port angle because this angle is thesame as that for which a vane is balanced in respect to fluid pressureforces acting on its opposite sides, and (subject to later mentionedexceptions) the camming interval a is limited in its maximum angularextent to this balanced pressure region.

Within each such port angle there are certain angular positions of thevanes which are of particular interest. Those angular positions will nowbe considered.

First, assume that in FIG. 16 the vane 168a is not in the position shownbut instead is approaching the far edge 175a of high pressure port a asthe drum 167 rotates clockwise. In the course of such approach the vane168a reaches an angular region wherein the flow of fluid from port 170::into the lower half of groove 166 is dynamically throttled by theprogressive closure of the gap between the leading edge 177a of the vaneand the far edge 175a of the port. Such throttling has the directconsequence of reducing the pressure on the leading edge ll77a of vane168a and on the lagging edge of the working vane 169a, the ultimateconsequence of the throttling thereby being to shift the work load fromvane 169a to vane 168a. While the described throttling action builds upan inequality of the fluid pressure forces acting on opposite sides ofvane 168a even before the leading side 177a of this vane reaches portedge 175a, a definite position at which this pressure inequality existsis the position 178a at which the center line of vane 163a is separatedby an angle c equal to t/ 2 from the port edge 175a towards which thevane is approaching. At this position the leading edge 177a of vane 168ajust registers with port edge 175a to completely cut 01f the fiow offluid from port 1741a. At position 178a, therefore, there is no questionbut that less fluid pressure force is exerted on the leading side ofvane 168a than on the lagging side thereof.

Second, as vane 169a approaches block 160a, the vane undergoes, asdescribed, an axial motion of displacement for the purpose of passing bythe block. Let us assume that it is desired that this passing by of theblock be accomplished with the minimum possible throw H of the vane. Forthis assumed condition, it will be evident that the vane must haveundergone its full axial displacement when the leading edge of the vanereaches the block. In practice, full displacement would have to beobtained slightly before the leading edge just registers with the nearedge of the block. This is so inasmuch as some clearance must be allowedfor. For analysis purposes, however, the position at which the assumedcondition of minimum possible H requires full displacement of the vaneis a position which will be taken as occurring where the leading edge ofvane 169a just registers with the edge adjacent thereto of block proper160a. When the leading edge is so positioned, the center line of vane169a is at the position 17911 which is spaced by the angle f equal to t/2 from the near edge of the block.

The angle q of any port minus the angles c and 1 within that port anglemay be defined as the vane sub-port angle 1' inasmuch as it is onlywithin this angle r that a vane is wholly underneath a port. From theforegoing, it is apparent that the sub-port angle r is given by theexpressrons:

Heretofore, it has been believed that the camming section associatedwith any port should terminate at its end towards the reaction block atan angular position which is spaced by greater than the angle i from thenear edge of the block proper in order thereby to permit use of theminimum possible axial throw H for the vane. It has also been believedthat the camming section at its edge away from the block shouldterminate at an angular position which is spaced by greater than anglefrom the edge of the port farthest from the reaction block. Thereasoning behind this latter belief is that, if the camming section wereto extend any further, the vane would be in axial motion while beingsubjected to unequal pressure forces on opposite sides, but, if the vanewere to be subjected to unequal lateral pressure while in axial motion,friction, stress and wear would be created by the binding of the vaneagainst one side of its slot as a result of the unbalance of lateralpressure thereon.

To summarize the above, it has previously been believed thatt he angularcamming interval a associated with a camming intervals a.

I have found that those previously held beliefs are mistaken, and that asignificant improvement in capacity or horsepower can be realized byproceeding contrary to those benefits. Specifically, I have found that,in contrast to what has previously been taught, the camming intervals ashould be increased in any one or more of the ways of (I) extending atowards the block to an angular position which in any event is closerthan t/2 to the rear edge of the block and which may be the center lineof the block, (II) extending a away from the block to an angularposition which in any event is spaced closer than 1/2 to that edge ofthe associated port which is the far edge in relation to the block, andwhich angular position may extend beyond such far edge, and (III)employing more than two vanes per block, whereby each vane workinginterval i is decreased to permit a corresponding increase in thecamming intervals a which lie to either side of that working interval.

FIG. 18 illustrates ways I and II of increasing carnrning intervals a.In respect to I, each of the camming sections 101 and 1% extend all theway to the center line 102 of the reaction block 56. In order to soincrease those camming sections it is necessary to increase the throw Hof the vanes beyond the maximum value of H which could be used if thecamming intervals terminated short of positions 179a. However, thepercentage increase in H which is necessary to carry the intervals a allthe way to the center line of the reaction block is small in relation tothe percentage increase in a which such increase in H permits. This isso for two reasons. First, inasmuch as the camming sections 101 and 103follow, as described, a curve for which both the first and secondderivatives are Zero at the ends of the camming sections, those sectionswill have segments of relatively flat profile at the ends thereofadjacent the reaction block, and, for those fiat profile segments, aincreases much faster than H. Second, forreasons heretofore described,the winged construction of the reaction block permits the block proper aof the axially selfadjusting block to be reduced to the optimum angularthickness of 2t, and such reduction of the block thickness keeps theincrease in H which is required to a much lower value than would benecessitated if the thickness of the block proper were to besubstantially in excess of 2!.

When the camming sections 101 and 163 are so extended to the center line102 of the reaction block, the portions of those sections extending fromangular positions 178a to center line 102 are equal to:

By comparison with (28) it will be seen that those portions alone of thecamming sections exceed the subport angle r of (28) which in turn islarger than the entire camming interval hitherto considered as thepractical maximum.

In respect to way II of increasing the camming intervals a, for sections101, 163, as shown by FIG. 18, those camming sections extend away fromthe reaction block beyond the positions 178a and in fact, beyond theedges a, 176a of ports 89 and 93 which are the far edges of those portsin relation to the reaction block. The segments of camming sections rer,103 which are to the far side of angular positions 178a are segmentsoccupying angular intervals wherein a vane is subject to an unbalance oflateral pressure forces. However, I have found that because the sections101 and 103 follow curves wherein the first and second derivatives arezero at the pointof joinder of each of those sections with the adjacentdwell section of the camming surface,

the outlying end segments of those sections are sufficiently flat inprofile to permit such sections to extend a short distance into theregion of pressure unbalance of the vanes. Specifically, each such endsegment may, at the least, extend far enough into the region of pressureunbalance to (1) permit clearance to be taken up between the cammingsurfaces and the cam follower end faces of the vanes, and, (2) stressthe vanes by a driving force P up to the value F max which is themaximum value permitted.

When tne camming sections 181 and 103 are extended only so far as theedges 175a, 176a of ports 89 and )9, the portions of those cammingsections between angular positions 179a and edges 175a, 175a areportions which each have an angular interval of:

180/B(1-1/n)--3t/2 (30) which is greater than the sub-port angle 1'given by (28), Thus, each of those portions of themselves exceed themaximum value of camming interval which has hitherto been consideredpractical.

A comparison of FIGS. 19, 4 and 20 with FIG. 17 demonstrates theincrease in the camming intervals a which is obtainable by increasingthe number of vanes. In FIG. 19 there are three vanes per block for eachof two blocks as compared to FIG. 17 wherein there are only two vanesper block for each of two blocks.

Let it be assumed for the structures of both FIGS. 17 and 19 that eachvane has an angular vane thickness t of 4 and that each camming intervala extends over only the sub-port angle 1'. Then applying Formula 28, thevalues for the intervals a in the FlG. 17 and FIG. 19 structures are,respectively, the angular values of 37 and 51. In other words, theeffect of increasing the number of vanes per block from two to three isto permit at the least a 38% increase in the value of the cammingintervals a. However, in the instance where the peripheral velocity v isfixed and where, as described, the maximum capacity (or horsepower) of amachine hence varies approximately as the square of a, a 38% increase ina results to an approximation, in an increase of 1.91 fold in maximumcapacity. Of course, if the camming intervals a are increased further byextending them, as described, beyond each of the angular positions 178aand 179a, the increase in maximum capacity becomes even greater. Forexample, if each of such intervals is extended to the center line oftheir corresponding reaction block and to the far edge of thecorresponding port, the intervals a in FIG. 19 become equal to 60 whichvalue is 62% greater than 37, whereby the increase in maximum capacityis over twofold.

The foregoing discussion makes evident the fact that as the workinginterval i per vane is decreased (by increasing the number of vanes perblock), such decrease permits an increase in the angle which can besubtended by the ports. When this increased angle is fully utilized asport angle, there is increased thereby the angle over which the vanesare balanced in respect to lateral fluid pressure forces, the latterangle in large part determining the practical angular extent of thecamming interval a. When advantage is taken under those conditions toincrease a, this leads to an increase in the maximum capacity of which amachine of given size is capable, and this increased maximum capacitycan be obtained whether the block angle b equals 2t or is of greatervalue. In this connection, it is to be noted that, for a constant valueof camming interval a, a decreased working interval resulting from anincrease in the number of vanes per block is a change in structure whichin no way adversely affects the capacity of the machine. This is so,inasmuch as when the working interval per vane is so decreased, thenumber of vanes which work over unit time is oifsettingly increased and,therefore, the capacity remains the same.

As the number of vanes is progressively increased, the maximum capacityof the machine is also progressively increased. For example, if thenumber of vanes is increased from three vanes per block as in FIG. 19 tofour vanes per block as in R6. 4, when the same assump tions are made asbefore (namely, that 1 equals 4 and that the camming interval :1 equalsthe sub-port angle r), then tor FlG. 4 the camming interval a has fromFormula 28 a value of 59.5 as compared to a value of 37 for FIG. 19. Aninterval of 59.5 is 61% greater than 37 and leads to a potentialimprovement of about 2.6 fold in the capacity of the machine.

As another example, if the number of vanes is further increased to sixper block as in FIG. 20, then, with the same assumptions as before, fromFormula 28 the camming interval a for FIG. 20 is 67. This 67 figure is81% greater and 12.6% greater than the camming intervals forrespectively, the structure shown in FIGS. 19 and 4, wherefore, themaximum capacity attainable in the FIG. 20 machine exceeds by 3.28 foldand 1.27 fold the maximum capacities in, respectively, the PEG. 19 andFIG. 4 machines.

Evidently, the technique of increasing the camming interval a byincreasing the number of vanes per block is not limited to a two-blockmachine but is applicable also to a machine having three or more blocksor to a machine having say, only one block per groove. For example, inthe case of a one block machine wherein the number of vanes per block isprogressively increased from two to four to six, with such increase invanes (and assuming that t equals 4 and a equals 1'),- the correspondingincrease in the camming interval a is (by Formula 28) from 82 to 127 to142.

Further, in order to realize an increase in capacity by increasing thenumber of vanes it is not necessary that the camming interval a beincreased to the maximum extent permitted by the decrease in workinginterval i resulting from the vane increase. Thus, using one blockmachines as an example, a six-vane one-block machine inherently permitsthe camming interval a to be greater than the limiting value for a whichcharacterizes a fourvane one-block machine (this limiting value beingrounded off to, say, For any value of a in the six-vane oneblock machinewhich exceeds the limiting value 135 for a in the four-vane one-blockmachine, the machine with the higher number of vanes per block will havea greater potential maximum capacity than the machine with the lowernumber of vanes per block. The same considera tions apply to machineshaving two or more blocks. As an illustration of this fact a machinewith three vanes per block and two blocks is capable of a bettercapacity than a machine with two vanes per block and two blocks for anycamming interval a of the three vane per block machine which exceeds thelimiting value for the two vane per block machine, this latter limitingvalue being rounded oil to, say 45.

The above-described embodiments being exemplary only, it will beunderstood that the invention hereof comprehends embodiments differingin form and/or detail from the above-described embodiments.

For example, the invention is of application to rotary motion alignedimpulsion machines in which there are a fractional number of vanes perblock as, say, a machine having five vanes and two reaction block pergroove. Further, although the embodiments described herein are suitablefor high speed operation, the invention hereof is applicable to rotarymotion aligned impulsion machines designed for use at any speed ofoperation.

While specific embodiments of the invention have been shown in which thecylindrical sleeve (or casing) is stationary and the drum rotates, theprinciples of the invention may be applied and used in machinerydesigned to have the sleeve (or casing) rotate while the drum remainsstationary. In other modifications, the vanes may more radially inradial (instead of axial) slots, the relatively rotatable members havingplanar faces, one face having an annular groove and the other having thereaction block aifixed thereto and seated in the groove. Such radialmachine would also differ from the axial machine shown in FIGS. 3 and 4in that the flow of fluid between the groove and the ports would be inan axial direction, the variations from dwell position of the camguiding surfaces for imparting transverse movement to the one or morevanes would be radial rather than axial variations, and, in respect tothe reaction block and vanes, what was axial in FIGS. 3 and 4 wouldbecome radial and what was radial in FIGS. 3 and 4 would become axial.As specific illustrations, in the radial machine the reaction blockwould project axially rather than radially from the stationary memberinto the annular groove of the rotor (although the extensions 150, 151would still project angularly from the reaction block), and, in a vaneof the type shown in FIG. 4, the apertures 120, 122 would run axiallythrough the vane between axially opposite margins thereof rather than(as specifically shown in FIG. 4) radially through the Vane betweenradially opposite margins thereof.

Accordingly, the invention is not to be considered as limited save as isconsonant with the scope of the following claims.

I claim:

1. Apparatus comprising, first and second members relatively rotatableabout a common axis, said second member having formed therein at leastone continuous fluid-receiving groove and at least one slot extendingtransversely from said groove to an extremity of said member remote fromsaid groove, at least one block seated in said groove in fixed positionrelative to said first member in the angular direction around said axis,a fluid inlet which communicates with said fluid receiving groove on oneside of said block and a fluid outlet which communicates with said fluidreceiving groove on the other side of said block, a vane transverselymovable in said slot between first and second positions at which,respectively, said vane obstructs said groove and said groove is unobstructed by said vane, an annular channel formed in said second memberaround said axis and disposed transversely from and open to saidextremity of said second member, and camming means disposed adjacentsaid extremity of said second member and having an annular cammingportion received in said annular channel to extend transverselythereinto from said extremity, said channel being disposed in saidsecond member to angularly transect said slot and to be bounded onopposite sides thereof by portions of said second member each containinga portion of said slot, said camming portion extending transversely intosaid channel to terminate in a camming surface extending around saidcamming portion and entirely insheathed by said second member, and saidcamming surface being in contact with said vane so as, during relativerotation of said members, to position said vane at said second positionwhen said vane is passing by said block and at said first position atintervening times.

2. Apparatus comprising, first and second members relatively rotatableabout a common axis, said second member having formed in a transverselycentral portion thereof at least one continuous fluid-receiving grooveand at least one slot extending transversely across said groove betweenopposite transverse extremities of such second member which are remotefrom said groove, at least one block seated in said groove in fixedposition relative to said first member in the angular direction aroundsaid axis, a fluid inlet which communicates with said fluid receivinggroove on one side of said block and a fluid outlet which communicateswith said fluid receiving groove on the other side of said block, a vanetransversely movable in said slot between first and second positions atwhich, respectively, said vane obstructs said groove and said groove isunobstructed by said vane, a pair of annular channels each formed insaid second member around said axis and each being disposed transverselyfrom and open to a respective one of said extremities of said secondmember, and a pair of camming means each 2% disposed adjacent arespective one of said extremities of said second member and each havingan annular camming portion received in said annular channel to extendfrom such extremity transversely into that member, each such channelbeing disposed in said second member to angularly transect said slot andto be bounded on opposite sides thereof by portions of said secondmember each containing a portion of said slot, each such camming portionextending transversely into the corresponding channel to terminate in acamming surface extending around the camming portion and entirelyinsheathed by said second member, and the two camming surfaces sopresent contacting transversely opposite faces of said vane so as,during relative rotation of said members, to position said vane at saidsecond position when said vane is passing by said block and at saidfirst position at intervening times.

3. Apparatus comprising, a drum rotatable about an axis and a stationarybushing surrounding said drum, said drum having formed therein at leastone annular fluid-receiving groove and at least one axial slot extendingfrom said groove to an axial end of said drum remote from said groove,at least one block in said groove in fixed position relative to saidbushing in the angular direction around said axis, a fluid inlet whichcommunicates with said fluid receiving groove on one side of said blockand a fluid outlet which communicates with said fluid receiving grooveon the other side of said block, a vane axially movable in said slotbetween first and second positions at which, respectively, said vaneobstructs said groove and said groove is unobstructed by said vane, anannular channel formed in said drum around said axis and disposedtransversely from and open to said end of said drum and a camming memberdisposed adjacent said drum end and having an annular flange received insaid annular channel to extend axially thereinto from said end thereof,said channel being disposed in said drum to angularly transect said slotand to be bounded on ra dially opposite sides by portions of said drumeach containing a portion of said slot, and the free end of said flangewithin said channel providing a camming surface which is entirelyinsheathed by said drum, and which contacts said vane so as, duringrotation of said drum, to position said vane at said second positionwhen said vane is passing by said block and at said first position atintervening times.

4. Apparatus comprising, a drum rotatable about an axis and a stationarybushing surrounding said drum, said drum having formed therein anannular groove in an axially central portion thereof and a plurality ofaxial slots extending across said groove between axially opposite endsof said drum remote from said groove, at least one block in said groovein fixed position relative to said bushing in the angular directionaround said axis, a fluid inlet which communicates with said fluidreceiving groove on one side of said block and a fluid outlet whichcommunicates with said fluid receiving groove on the other side of saidblock, a plurality of vanes each seated in a respective one of saidslots and each being axially movable in its slot between first andsecond positions at which, respectively, such vane obstructs said grooveand said groove is unobstructed by such vane, a pair of annular channelseach formed in said drum around said axis and each being disposedtransversely from and open to a respective one of said ends of saiddrum, and a pair of camming members each disposed adjacent a respectiveone of said drum ends and each having an annular flange received in saidannular channel to extend axially from such end into said drum, eachsuch channel being disposed in said drum to angularly transect all ofsaid slots and to be bounded on radially opposite sides by portions ofsaid drum each containing a portion of each of said slots, and each suchflange providing at the channelreceived free end thereof a cammingsurface entirely insheathed by said drum, the two camming surfaces sopresent contacting axially opposite faces of said vane so

